Method of protecting determinate soybean from damage by a plant pathogen

ABSTRACT

The present invention can provide a method having superior safety for protecting determinate soybean from damage by a plant pathogen. The method includes a step of applying mefentrifluconazole to foliage of determinate soybean, seeds of determinate soybean or a soil of the cultivation area of determinate soybean, wherein the application rate of mefentrifluconazole is 20 to 500 g per hectare of cultivation area.

TECHNICAL FIELD

This application claims priority to and the benefit of Japanese PatentApplication No. 2019-073972 filed on Apr. 9, 2019 and U.S. patentapplication Ser. No. 16/396,343 filed on Apr. 26, 2019, the entirecontents of which are incorporated herein by reference.

The present invention relates to a method of protecting determinatesoybean from damage by a plant pathogen.

BACKGROUND ART

Hitherto, a method of applying mefentrifluconazole has been known, as amethod for controlling a plant pathogen on soybean (see PatentLiterature 1). Also, several types of soybean such as determinatesoybean, indeterminate soybean and semi-determinate soybean are known(see Non Patent Literature 1). However, it is not known that determinatesoybean, especially, can be safely protected from damage by a plantpathogen by applying mefentrifluconazole at certain application rate.

CITATION LIST Patent Literature

-   PTL 1: WO 2013/007767 pamphlet

Non Patent Literature

-   NPL 1: Crop Science 12 (1972), 235-239.

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a method havingsuperior safety for protecting determinate soybean from damage by aplant pathogen.

Solution to Problem

The present inventor has found out that determinate soybean can besafely protected from damage by a plant pathogen by applyingmefentrifluconazole at certain application rates to foliage ofdeterminate soybean, seeds of determinate soybean, or a soil ofcultivation area of determinate soybean.

The present invention includes the following aspects [1] and [2].

[1] A method of protecting determinate soybean from damage by a plantpathogen in a cultivation area of determinate soybean, the methodincluding a step of applying mefentrifluconazole to foliage ofdeterminate soybean, seeds of determinate soybean or a soil of thecultivation area of determinate soybean, wherein the application rate ofmefentrifluconazole is 20 to 500 g per hectare of the cultivation area.

[2] The method according to [1], wherein mefentrifluconazole is appliedto foliage of determinate soybean.

Advantageous Effects of Invention

Determinate soybean can be safely protected from damage by a plantpathogen according to the present invention.

DESCRIPTION OF EMBODIMENTS

The method of protecting determinate soybean from damage by a plantpathogen of the present invention (hereinafter, sometimes referred to as“present method” or “method of the present invention”) includes a stepof applying mefentrifluconazole to foliage of determinate soybean, seedsof determinate soybean or a soil of cultivation area of determinatesoybean.

Mefentrifluconazole is a triazole-type sterol biosynthesis inhibitor,and can be manufactured by a known method.

Soybean in the present invention is a plant species generally describedas Glycine max in scientific name, but it also includes ‘biologicallyidentical species having the homogeneous genome to Glycine max’ such aswild soybean (Glycine soja, also known as Glycine max subsp. soja).Determinate soybean in the present method is a variety group among theaforementioned soybean showing a genotype dt1/dt1 at the locus (Dt1)relating to the growth habit. Varieties showing Dt1/dt1 or Dt1/Dt1 onthe locus become indeterminate soybean or semi-determinate soybeandepending on the condition on another locus (Dt2) relating to the growthhabit.

In the present method, variations within determinate soybean are notparticularly limited as long as the determinate soybean is a varietywhich is usually cultivated. For example, determinate soybean belongingto diverse maturity groups from early-maturing to late-maturing can beused. Also, the varieties are not limited by diverse intended usages ofthe harvest of determinate soybean. For example, determinate soybean forany of the intended usages such as seed production, ornamentals, greenmanures, silage, grains, and the like can be used. For grains,determinate soybean for any of the intended usages such as food, oilextraction, feed, flour milling, and the like can be used.

Examples of determinate soybean varieties include Toyomusume,Sachiyutaka, Fukunari, Tambaguro, Enrei, Hobbit87, Asgrow AG53X6,Credenz CZ5225LL and the like. Examples of soybean which does not belongto determinate soybean include Williams 82, Harosoy, Kurosengoku,Tsurusengoku, wild soybean, Asgrow AG4934, Credenz CZ4590RY and thelike. Although the weight of seeds of determinate soybean which can beused in the present method is not particularly limited, a seed weight ofdeterminate soybean is usually within a range of 20 to 600 mg/seed, andmore preferably 250 to 500 mg/seed.

The determinate soybean may be the one producible by natural crossing,plants producible by a mutation, F1 hybrid plants, or transgenic plants(also called genetically modified plants). These plants generally havecharacteristics such as tolerance to herbicides, accumulation ofsubstances harmful to insect pests, reduction in sensitivity todiseases, increase in yield potential, improvement in resistance tobiotic or abiotic stress factors, accumulation of substances, andimprovement in preservability and processability.

The F1 hybrid plants are those which are each a first filial hybridobtained by crossing two different varieties with each other and usuallyhave characteristics of heterosis, which is a nature of having moreexcellent trait than both of the parents. The transgenic plants arethose which are obtained by introducing an exogeneous gene from otherorganisms such as microorganisms and have characteristics like thosethat cannot be easily obtained by crossbreeding, mutation induction, ornatural recombination in natural environments.

Examples of the technologies used to create the above plants includeconventional type variety improvement technologies; geneticrecombination technologies; genome breeding technologies; new breedingtechnologies; and genome editing technologies. The conventional typevariety improvement technologies are specifically technologies forobtaining plants having desired properties by a mutation and crossing.The genetic recombination technologies are technologies in which atarget gene (DNA) is extracted from a certain organism (for example,microorganism) to introduce it into a genome of a different targetorganism, thereby imparting new properties to the organism, andantisense technologies or RNA interference technologies for impartingnew or improved characteristics by silencing a certain genes existing inplants. The genome breeding technologies are those improving breedingefficiency by using genome information and include DNA marker (alsocalled genome markers or genetical markers) breeding technologies andgenomic selection. For example, the DNA marker breeding is a method inwhich a progeny having a target gene with a useful trait is selectedfrom a lot of cross progenies by using a DNA marker which is a DNAsequence and is a marker of the presence position of a gene with aspecific useful trait on a genome. This method has the characteristicsthat the time required for breeding can be efficiently reduced byanalyzing the cross progeny using a DNA marker when the progeny is ajuvenile plant.

Also, the genomic selection is a technique in which a prediction formulais created from a phenotype obtained in advance and genome informationto predict the characteristics from the prediction formula and thegenome information without any evaluation of the phenotype and istechnologies contributing to improvement in efficient breeding. The newbreeding techniques are a generic term of variety-improvement(=breeding) techniques that are combinations of molecular biologicaltechniques. Examples of the new breeding techniques includecisgenesis/intragenesis, introduction of an oligonucleotide-directedmutation, RNA-dependent DNA methylation, grafting onto a GM rootstock orscion, reverse breeding, agroinfiltration, and seed productiontechnology (SPT). The genome editing technologies are those in whichgenetic information is transformed in a sequence-specific manner whichenables, for example, deletion of a base sequence, substitution of anamino acid sequence, and introduction of an exogenous gene. Examples oftools for these techniques include sequence-specific genome modificationtechniques such as zinc-finger nuclease (ZFN), TALEN, CRISPR/Cas9,CRISPER/Cpfl, and Meganuclease which each enable sequence-specific DNAscission and CAS9 Nickase and Target-AID which are each created bymodifying the aforementioned tools.

Examples of the plants mentioned above include plants listed in GMAPPROVAL DATABASE of genetically modified crops in the electronicinformation site (http://www.isaaa.org/) of INTERNATIONAL SERVICE forthe ACQUISITION of AGRI-BIOTECH APPLICATIONS (ISAAA). More specifically,these examples include herbicide tolerant plants, insect pest resistantplants, disease resistant plants, and quality modified (for example,increase or decrease in content of a certain component or change incomposition) plants of products (for example, starch, amino acid, andfatty acid), fertile trait modified plants, abiotic stress tolerantplants, or plants modified in traits relating to growth and yield.

Examples of plants to which tolerance to herbicides is imparted aregiven as follows.

The tolerance to herbicides is obtained, for example, by reducing thecompatibility of a chemical with its target, by rapid metabolism (forexample, breakdown or modification) resulting from the expression of achemical deactivation enzyme, or by inhibiting the incorporation of achemical into a plant body or the transfer of the chemical in the plantbody.

The plants to which herbicide tolerance is imparted by geneticrecombination technologies include plants to which tolerances to thefollowing inhibitors are imparted by genetic recombination technologies:4-hydroxyphenyl pyruvate dioxygenase (hereinafter abbreviated as HPPD)inhibitors such as isoxaflutole and mesotrione, acetolactate synthetase(hereinafter abbreviated as ALS) inhibitors such as imidazolinone typeherbicides including imazethapyr and sulfonylurea type herbicidesincluding thifensulfuron-methyl, 5-enolpyruvylshikimate-3-phosphatesynthase (hereinafter abbreviated as EPSP) inhibitors such asglyphosate, glutamine synthetase inhibitors such as glufosinate, auxintype herbicides such as 2,4-D and dicamba, oxynil type herbicidesincluding bromoxynil, and protoporphyrinogen oxidase (herein afterabbreviated as PPO) such as flumioxazin.

In the present method, mefentrifluconazole is usually used after makingformulation by mixing with a carrier such as a solid or liquid carrier,and adding auxiliary agents for formulation such as a surfactant asnecessary. In the case of making formulation, preferable formulationtype is a soluble liquid, soluble granule, an aqueous suspensionconcentrate, oil-based liquid suspension, wettable powder, waterdispersible granule, granule, aqueous emulsion, oil-based emulsion, andemulsifiable concentrate. More preferable formulation type is aqueoussuspension concentrate. Moreover, a formulation containingmefentrifluconazole singly as an active ingredient may be independentlyused or may be tank-mixed with a formulation containing other fungicidesas active ingredients. Also, a formulation containingmefentrifluconazole and other fungicide may be used. Also, a formulationcontaining mefentrifluconazole and other fungicide as active ingredientsmay be tank-mixed with a formulation containing, as active ingredients,fungicide different from the above fungicides. The content of the activeingredients (mefentrifluconazole or a total of mefentrifluconazole andother fungicides) in the formulation is usually within a range of 0.01to 90% by weight, and preferably 1 to 80% by weight.

In the present method, “applying mefentrifluconazole to foliage ofdeterminate soybean” means to apply mefentrifluconazole to foliage ofdeterminate soybean planted in the cultivation area.

In the present method, when applying mefentrifluconazole to foliage ofdeterminate soybean or a soil of the cultivation area of determinatesoybean, the application is usually conducted using a spray dilutionprepared by mixing a formulation containing mefentrifluconazole withwater. These applications may be conducted uniformly on the cultivationarea, or may be conducted locally as a spot treatment onto foliage ofdeterminate soybean or the soil around the determinate soybean. Theamount of the dilution to be sprayed is usually 10 to 1000 L, preferably100 to 500 L, and more preferably 140 to 300 L per hectare ofcultivation area of determinate soybean though no particular limitationis imposed on it.

In the present method, when applying mefentrifluconazole to seeds ofdeterminate soybean, the treatment is usually conducted by coating orspraying seeds with a dilution prepared by mixing a formulationcontaining mefentrifluconazole with water.

In the present method, the application rate of mefentrifluconazole isusually within a range of 20 to 500 g, preferably 40 to 200 g, and morepreferably 60 to 150 g per hectare of cultivation area of determinatesoybean. Examples of the specific application rates ofmefentrifluconazole include 30 g, 50 g, 70 g, 80 g, 100 g, 120 g, 250 g,300 g, and 400 g per hectare of cultivation area of determinate soybean.These application rates can be described with “approximately.”“Approximately” means plus/minus 10%, so, for example, “approximately100 g per hectare” means “90 to 110 g per hectare.”

In the present method, when applying mefentrifluconazole locally as aspot treatment onto foliage of determinate soybean or the soil aroundthe determinate soybean, usually 0.001 to 2 mg of mefentrifluconazole isapplied per determinate soybean plant. Preferably, 0.01 to 1 mg ofmefentrifluconazole is applied per determinate soybean plant. Forexample when 0.5 mg of mefentrifluconazole is applied locally per plantas a spot treatment and 400,000 plants are grown per hectare ofcultivation area, the application rate of mefentrifluconazole is 200 gper hectare of cultivation area of determinate soybean.

In the present method, when applying mefentrifluconazole to seeds ofdeterminate soybean, 0.001 to 1 mg of mefentrifluconazole is usuallyapplied per seed of determinate soybean. Preferably 0.01 to 0.2 mg ofmefentrifluconazole is applied per seed of determinate soybean. Seedstreated with mefentrifluconazole are usually sown uniformly tocultivation area so that the application rates of mefentrifluconazoleper hectare of cultivation area may be a desired range. For example,when 0.1 mg of mefentrifluconazole is applied per seed, and 1,000,000seeds are sown per hectare of cultivation area, the application rate ofmefentrifluconazole is 100 g per hectare of cultivation area.

Although a period of time for conducting the present method is notparticularly limited, the period of time is usually within a range from5 a.m. to 9 p.m., and the photon flux density at land surface of theplace where the present method is conducted is usually 10 to 2500μmol/m²/s.

The spray pressure when conducting the present method is usually 30 to120 PSI and preferably 40 to 80 PSI though no particular limitation isimposed on it. Here, the spray pressure is a set value just before thedilution is introduced into the nozzle.

The nozzle used in the present method may be flat-fan nozzles ordrift-reducing nozzles. Examples of flat-fan nozzles include Teejet110series and XR Teejet110 series manufactured by Teejet Company. Whenusing these nozzles, the spray pressure is generally 30 to 120 PSI andthe volume median diameter of liquid droplets discharged from the nozzleis usually less than 430 micro meter. The drift-reducing nozzle is anozzle which leads to less drift compared with a flat-fan nozzle andwhich is called an air induction nozzle or pre-orifice nozzle. Thevolume median diameter of a liquid droplet discharged from thedrift-reducing nozzle is usually 430 micro meter or more.

In the present method, when applying mefentrifluconazole to seeds ofdeterminate soybean, the application is usually conducted before sowingthe seeds. In the present method, when applying mefentrifluconazole tofoliage of determinate soybean, the application is conducted usuallybetween just after emergence of determinate soybean and its harvestingstage, more preferably between 1 leaf stage of determinate soybean andits grain filling stage, and further preferably between 2 leaf stage ofdeterminate soybean and its flowering stage.

In the present method, seeds of determinate soybean may be treated withone or more compounds selected from the group consisting of insecticidalcompounds, nematicidal compounds, fungicidal compounds exceptmefentrifluconazole, and plant growth regulators. Examples of compoundsto be used for the seed treatment include neonicotinoid compounds,diamide compounds, carbamate compounds, organophosphorous compounds,biological nematicidal compounds, other insecticidal compounds andnematicidal compounds, strobilurin compounds, metalaxyl compounds, SDHIcompounds, other fungicidal compounds except mefentrifluconazole, andplant growth regulators.

Plant pathogens in the present method are usually fungi. Examples ofFungi include Ascomycota, Basidiomycota, Blasocladiomycota,Chytridiomycota, Mucoromycota and Olpidiomycota. Examples of specificplant pathogens include the following. The words in parentheses isdamage caused by the plant pathogen (plant disease).

Cercospora kikuchii (soybean Cercospora blight), Elsinoe glycines(soybean scab), Diaporthe phaseolorum var. sojae (soybean pod and stemblight), Phakopsora pachyrhizi (Asian soybean rust), Corynesporacassiicola (soybean target spot), Colletotrichum glycines+Colletotrichumtruncatum (soybean anthracnose), Rhizoctonia solani (soybean root rot),Septoria glycines (soybean brown spot), Cercospora sojina (frogeye leafspot), Sclerotinia sclerotiorum (soybean white mold), Microsphaeradiffusa (soybean powdery mildew), Phytophthora sojae (soybean stem androot rot), Peronospora manshurica (soybean downy mildew), Fusariumvirguliforme (soybean sudden death syndrome), Calonectria ilicicola(soybean root necrosis), and Diaporthe longicolla (soybeanDiaporthe/Phomopsis complex).

In the above plant pathogens, variations within the species are notparticularly limited. Namely, the pathogens also include any plantpathogens having reduced sensitivity (or resistance) to specificfungicides. The reduced sensitivity may be attributed to a mutation at atarget site (target site mutations), or may be attributed to a factorother than target site mutation (non-target site mutations). Target sitemutations include amino acid substitutions in target proteins caused bya mutation in the corresponding open reading frame, and over expressionof the target proteins caused by deletion of a suppressor sequence or anincrease of an enhancer sequence at the promotor region, oramplification of gene copy number. The factors of resistance bynon-target site mutations include acceleration of efflux of fungicidescoming into cells out of the cells by ABC transporter and MDStransporter and the like. It also includes detoxification of fungicidesby metabolism.

Examples of aforementioned specific fungicides include nucleic acidsynthesis inhibitors (such as phenylamide fungicides, acylamino acidfungicides, and DNA topoisomerase type II fungicides), mitosis and celldivision inhibitors (such as MBC fungicides, and N-phenylcarbamatefungicides), respiration inhibitors (such as QoI fungicides, QiIfungicides, and SDHI fungicides), amino acid synthesis and proteinsynthesis inhibitors (such as anilinopyrimidine fungicides), signaltransduction inhibitors (such as phenylpyrrole fungicides, anddicarboximide fungicides), lipid synthesis and cell membrane synthesisinhibitors (such as phosphorothioate fungicides, dithiorane fungicides,aromatic hydrocarbyl fungicides, heteroaromatic fungicides, andcarbamate fungicides), sterol biosynthesis inhibitors (for example, DMIfungicides (such as triazoles), hyroxyanlide fungicides, oraminopyrazolone fungicides), cell wall synthesis inhibitors (such aspolyoxin fungicides, and Carboxylic acid amide fungicides), melaninsynthesis inhibitors (such as MBI-R fungicides, MBID fungicides, andMBI-P fungicides), and other fungicides (such as cyanoacetamidoximfungicides, and phenylacetamide fungicides).

In the present method, mefentrifluconazole may be used in combinationwith one or more other fungicides. For here, using in combinationincludes tank-mix, pre-mix, and sequential treatment. In the case ofsequential treatment, the order of the treatment is not particularlylimited.

In the present method, fungicide used in combination withmefentrifluconazole is preferably pyraclostrobin, fluopyram orfluxapyroxad.

When aforementioned fungicide is used in combination withmefentrifluconazole, the weight ratio of mefentrifluconazole to otherfungicide is usually within a range of 1:0.001 to 1:100, preferably1:0.01 to 1:10, and more preferably 1:0.1 to 1:5. Examples of thespecific weight ratios include 1:0.02, 1:0.04, 1:0.06, 1:0.08, 1:0.2,1:0.4, 1:0.6, 1:0.8, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, and 1:4. These weightratios may be described with approximately. Approximately meansplus/minus 10%, so, for example “approximately 1:2” means 1:1.8 to1:2.2.

The cultivation of determinate soybean in the present invention can bemanaged according to the plant-nutrition in the common crop cultivation.The fertilization system may be based on Precision Agriculture adoptingvariable rate application or may be conventionally uniform one. Inaddition, nitrogen fixation bacteria and mycorrhizal fungi may beinoculated by seed treatment.

EXAMPLES

The present invention will be explained by way of examples, but thepresent invention should not be limited thereto.

Example 1

Determinate soybean is sown to a pot filled with a soil. It is incubatedfor 7 days in a greenhouse. Mefentrifluconazole spray liquid (preparedby diluting an aqueous suspension concentrate of mefentrifluconazolewith water) is uniformly sprayed onto the foliage of determinate soybeanat the amount of 200 L per hectare so that the application rate ofmefentrifluconazole may be 500 g per hectare. On the next day of thespraying, a pathogen of Asian soybean rust (Phakopsora pachyrhizi) isinoculated to the foliage of determinate soybean. The determinatesoybean is incubated in a greenhouse for 14 days from the inoculation,and then fresh weight of the aerial part of the determinate soybean ismeasured. It is confirmed that the fresh weight is equivalent to that ofthe control where determinate soybean is not treated withmefentrifluconazole and the pathogen is not inoculated(no-treatment-no-inoculation control) and is bigger than that of thecontrol where determinate soybean is not treated withmefentrifluconazole and the pathogen is inoculated(no-treatment-inoculation control).

Comparative Example 1

The same procedure of the example 1 is repeated except for replacingdeterminate soybean with indeterminate soybean or semi-determinatesoybean. It is confirmed that the fresh weight of indeterminate soybeanor semi-determinate soybean is smaller than that of the correspondingno-treatment-no-inoculation control and is equivalent to that of thecorresponding no-treatment-inoculation control.

Example 2

Seeds of determinate soybean are coated with a mefentrifluconazoleaqueous suspension concentrate so that the amount of mefentrifluconazoleto be applied to each seed may be 0.2 mg. Then, the determinate soybeanseeds are sown to a pot filled with a soil at a sowing rate of 100,000seeds per hectare. That is, the application rate of mefentrifluconazoleis 20 g per hectare. Then, the determinate soybean is incubated in agreenhouse for 10 days, followed by inoculating a pathogen of Asiansoybean rust (Phakopsora pachyrhizi) to the foliage of determinatesoybean. The determinate soybean is incubated in a greenhouse for 14days from the inoculation, and then the fresh weight of the aerial partof the determinate soybean is measured. It is confirmed that the freshweight is equivalent to that of the control where determinate soybean isnot treated with mefentrifluconazole and the pathogen is not inoculated(no-treatment-no-inoculation control) and is bigger than that of thecontrol where determinate soybean is not treated withmefentrifluconazole and the pathogen is inoculated(no-treatment-inoculation control).

Comparative Example 2

The same procedure of the example 2 is repeated except for replacingdeterminate soybean with indeterminate soybean or semi-determinatesoybean. It is confirmed that the fresh weight of indeterminate soybeanor semi-determinate soybean is smaller than that of the correspondingno-treatment-no-inoculation control and is equivalent to that of thecorresponding no-treatment-inoculation control.

Example 3

Determinate soybean is sown to a pot filled with a soil at a sowing rateof 1,000,000 seeds per hectare. The determinate soybean is incubated for10 days in a greenhouse, and then mefentrifluconazole dilution liquid(prepared by diluting an aqueous suspension concentrate ofmefentrifluconazole with water) is dripped onto the primary leaf ofdeterminate soybean so that the amount of mefentrifluconazole to beapplied to each plant may be 0.2 mg. That is, the application rate ofmefentrifluconazole is 200 g per hectare. On the next day of theapplication, a pathogen of Asian soybean rust (Phakopsora pachyrhizi) isinoculated to the foliage of determinate soybean. The determinatesoybean is incubated in a greenhouse for 14 days from the inoculation,and then fresh weight of the aerial part of the determinate soybean ismeasured. It is confirmed that the fresh weight is equivalent to that ofthe control where determinate soybean is not treated withmefentrifluconazole and the pathogen is not inoculated(no-treatment-no-inoculation control) and is bigger than that of thecontrol where determinate soybean is not treated withmefentrifluconazole and the pathogen is inoculated(no-treatment-inoculation control).

Comparative Example 3

The same procedure of the example 3 is repeated except for replacingdeterminate soybean with indeterminate soybean or semi-determinatesoybean. It is confirmed that the fresh weight of indeterminate soybeanor semi-determinate soybean is smaller than that of the correspondingno-treatment-no-inoculation control and is equivalent to that of thecorresponding no-treatment-inoculation control.

Example 4

Seeds of two varieties of determinate soybean were separately dipped ina mefentrifluconazole dilution liquid (prepared by diluting an aqueoussuspension concentrate of mefentrifluconazole with water) so that theamount of mefentrifluconazole to be applied to each seed might be 0.2mg. Then, the determinate soybean seeds were sown to a pot filled with asoil at a sowing rate of 1,000,000 seeds per hectare. That is, theapplication rate of mefentrifluconazole was 200 g per hectare. Eachdeterminate soybean was incubated in a greenhouse for 11 days from thesowing, and then a pathogen of Asian soybean rust (Phakopsorapachyrhizi) was inoculated to the foliage of each determinate soybean.Each determinate soybean was incubated in a greenhouse for 7 days fromthe inoculation, and then fresh weight of the aerial part of eachdeterminate soybean was measured. The fresh weight is referred to as‘the fresh weight in treatment plot’.

As a control experiment, the same procedure was repeated except thatdipping treatment with mefentrifluconazole dilution liquid and theinoculation of the pathogen were not conducted. The fresh weightobtained in the control experiment is referred to as ‘the fresh weightin control plot’.

The results are shown in Table 1. As shown in Table 1, each determinatesoybean was successfully protected from the damage by the pathogen.

TABLE 1 Fresh weight Fresh weight in treatment in control Treatment/Variety/ plot (A) plot (B) control ratio growth habit (mg/plant)(mg/plant) (100 × A/B) Toyomusume/ 4.92 4.67 105 Determinate Tambaguro/7.17 6.89 104 Determinate

Comparative Example 4

The same procedure of the example 4 was repeated except for replacingtwo varieties of determinate soybean with two varieties of indeterminatesoybean. The results are shown in Table 2. As shown in Table 2, eachindeterminate soybean was not successfully protected from the damage bythe pathogen.

TABLE 2 Fresh weight Fresh weight in treatment in control Treatment/Variety/ plot (A) plot (B) control ratio growth habit (mg/plant)(mg/plant) (100 × A/B) Kurosengoku/ 1.40 2.06 68 Indeterminate Harosoy/2.08 3.74 55 Indeterminate

Example 5

Two varieties of determinate soybean were sown to a pot filled with asoil at a sowing rate of 1,000,000 seeds per hectare. Then eachdeterminate soybean was incubated for 8 days in a greenhouse. Amefentrifluconazole dilution liquid (prepared by diluting an aqueoussuspension concentrate of mefentrifluconazole with water) is drippedonto the apical bud of determinate soybean plants so that the amount ofmefentrifluconazole to be applied to each plant might be 0.5 mg. Thatis, the application rate of mefentrifluconazole was 500 g per hectare.Three days after the application, a pathogen of Asian soybean rust(Phakopsora pachyrhizi) was inoculated to the foliage of eachdeterminate soybean. Each determinate soybean was incubated in agreenhouse for 7 days from the inoculation, and then fresh weight of theaerial part of each determinate soybean was measured. The fresh weightis referred to as ‘the fresh weight in treatment plot’.

As a control experiment, the same procedure was repeated except thatdripping treatment with mefentrifluconazole dilution liquid and theinoculation of the pathogen were not conducted. The fresh weightobtained in the control experiment is referred to as ‘the fresh weightin control plot’.

The results are shown in Table 3.

TABLE 3 Fresh weight Fresh weight in treatment in control Treatment/Variety/ plot (A) plot (B) control ratio growth habit (mg/plant)(mg/plant) (100 x A/B) Toyomusume/ 3.97 4.67 85 Determinate Tambaguro/5.65 6.89 82 Determinate

Comparative Example 5

The same procedure of the example 5 was repeated except for replacingtwo varieties of determinate soybean with two varieties of indeterminatesoybean. The results are shown in Table 4.

As shown in Tables 3 and 4, determinate soybeans were protected muchmore effectively compared with indeterminate soybeans.

TABLE 4 Fresh weight Fresh weight in treatment in control Treatment/Variety/ plot (A) plot (B) control ratio growth habit (mg/plant)(mg/plant) (100 × A/B) Kurosengoku/ 1.00 2.06 49 Indeterminate Williams/82 0.77 1.96 39 Indeterminate

INDUSTRIAL APPLICABILITY

Determinate soybean can be safely protected from damage by a plantpathogen according to the present invention.

1. A method of protecting determinate soybean from damage by a plantpathogen in a cultivation area of determinate soybean, the methodcomprising a step of applying mefentrifluconazole to foliage ofdeterminate soybean, seeds of determinate soybean or a soil of thecultivation area of determinate soybean, wherein the application rate ofmefentrifluconazole is 20 to 500 g per hectare of the cultivation area.2. The method according to claim 1, wherein mefentrifluconazole isapplied to foliage of determinate soybean.